Airship mcoring method and apparatus



Jan. 10, 1933. c. 'B. FRITSCHE 1,893,584

AIRSHIP MOORING METHOD AND APPARATUS Original Filed Jan. is, 1950 2 Sheets-Sheet 1 INVENTOR Carl B. Frz'lscha BY I g i ATTORNEY Jan. 10,' 1933. c. a. FRITSCHE AIBSHIP MOORING METHOD AND APPARATUS Original Filed Jan. 18; 1930 2 Sheets-Sheet 2 INVENTOR Li] C ar/fif'rz'lsclze I BY Patented Jan. 10, 1933 unites s'r CARL .B. FRITSCHE, OF DETROIT, MICHIGAN, ASSIGNOE T0 AIRCRAFT DEVELOPMENT CORPORGKTEGN, .01 DETRGIT,'I1IICIEIGAII, CORPLRATTGIT OE I'LZCHIG'AN AIRSHIP MC'QEENG METHOD AND AIPP'ARATUS Application filed January 18, 1936,7Seria1 No. 421,6/l5. Renewed May '26, 1932.

This invention relates to airshipsbut more particularly to their construction which makes the airship capable of landing on water and bringing them down for a water 5 landing and mooring,while it also involves the method of mooring airships onwater it-h effective stable flotaiion.

For the purposes of my invention a construction of airship has been provided which will permit its landing with its own crew, and thereafter, as desired,to provide for taking off from the water,all of the operations being under control of the crew on board the ship. This is effected by providing a nacelle keel of suitable dimensions for't-he particular design and type of airship in questiomthe keel being watertight andextendin g v from the lower surface of the hull skin, the nacelle being airtight in part at least,soas to provide a suliiciently large space-into which water may be admitted, as desired, and from which the water may be ejected in part or whole, either fortrimming the shiporfor lightening the ship when'it'is desiredto rise from'the water. Such anacelle heel is also arranged to minimize the parasite air resistance when't-he ship is in flight, "and also to provide a minimum of resistance-tothe flow of water when moored on the Water. then q moored on the water usuallybybow-line,'or

as may belby a bridle, either to ground-mast,

or to a ship or other mooring float or anchor- I age, the airship will swing by-thewvind. Un-

der certain conditions of mooring there Wlll be a flow of surface water toward the stern of theship, so that the sub-structure or supplementary water-riding hull is stream-lined to reduce the strain on the mooring lines, as well as to reduce to-aminimumany water resistance while the nacelleisnstill in Contact with the water at the time that the'ship is gotten under way, ortaxyingfrom; the'lan'ding 'to its mooring. Arudder mayialsobe provided in order'to aid in stabilizing the position of'the ship in'the wind, in conjunction with the air rudders on'the ships hull, to meet any conditions ofvrolling,.or to maneuver the ship-from any purpose when landed on the water. The interior ofthe flotation or ballast keelimay also be dividedzinto two or morecompartnients by bulkheads, andathe ballast control in each maybe separatelymanipulated for the purpose of more definite trim ofthe longitudinal axis of the ship, or otherwise. I 1

While providing for the stable flotation, "I also aim to .providethe method, and the means self-contained for operation by the ships crew, for bringing the ship from entire air buoyancy tothe surface of the water. It will be understood .thatin maneuvering the ship inthe air it may be brought ,above'the water at the desired place, or approximately so depending uponvarious conditions. While it may thenfhave an altitude above water level which it is desired to reduce gradually in order to bring thefship to ,theisurface most safely, I provide suitable means .to lower from the ship I by self-containedapparatus operatedion board, that will reach the water andaccumul-atea suitable amountof water to offset the buoyancy of the ship, and then by manipulation on board, to draw the ship downto the surface. I have found thatlowering by suitable linesa cage of sponges, preferably primed, or several cages .of sponges, they will quicklynbsorbapproxt mately twenty-one times :and more, oftheir weight of salt water, and thereforezprovi'de a vertical anchor which can be-made :ofian aggregate suflicient to properly counteract the liftof the ship,without .valving hydrogenorhelium. In that manner the water landing can :be made without lossof the valuable buoyant gas, so that after reaching the surface ofthe water the ballastikeel may be allowed to fill to the desired trim for maintainingthe water surface moorin Such lift-anchors-may bevpreferably in pairs, one on-eitherjside forward and: one on eitherside aft, and will also serve the purpose to prevent rolling ofthe ship when the nacelle keel is partially vemersed. When however it is desired to clear away ready for flight, the spongeanchors canobe squeezed eliminating ninety-five per cent of their 'weight'when full of water, and the water in the ballast keelcan then be forced out, and on account of the surplus buoyancymai-ntained due to. not having valved any gas, the

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ship will then rise without difliculty ready for maneuvering in the air.

While this invention may take various forms of construction, and of course modifications in dimensions and arrangement, in the accompanying drawings specific embodiments are illustrated, in which:

Fig. I is a side elevation of a rigid airship moored by the nose, and in stable flotation on the water.

Fig. II is a bottom view of the nacelle keel.

Fig. III is a cross-section of the keel in the plane IIIIII, of the previous figures.

Fig. IV is a cross-section on the plane IV IV, of Fig. II.

Fig. V is a cross-section on an enlarged scale of the ballast keel, in the plane III- III of Fig. II, including a fragmentary portion of the adjacent airship hull structure.

Fig. VI is a side elevation of an airship with lowering sock or anchors when about to make a water surface landing.

Fig. VII is a front elevation of Fig. VI, showing the ship on the surface of the water,power cars omitted.

Fig. VIII is a fragmentary sectional view of the dry keel section containing the anchor manipulating means.

Fig. IX is a section of one form of a sponge cage, in vertical section, serving to evacuate automatically a substantial part of the water content of the sponge cells.

In the mooring arrangement shown in Fig. I, an airship 1 is moored by the bow line 2, to a moo-ring tower 3 located as on a small island, with mooring connections 3 which permit the bow line to be adjusted, such as maintaining it horizontal for the stable flotation position of the. ship. The mooring tower attachment being variable vertically, permits the initial mooring followed by bringing the ship vertically downward as by the surplus-weight-anchors, or otherwise, until the ship is moored in stable flotation on the surface of the water.

The nacelle keel 4 is secured to the airship hull structure on the bottom amidships, while its exact longitudinal position will depend upon the structure of the ship. In certain types of ship it may be preferable to have two nacelle keels generally parallel and taking the form of kelson keels, whereby the rolling of the ship when moored on the wa ter may be minimized by regulation of the ballast in the two nacelles. Vhile pairs of right and left supplementary weight wateranchors, in sets of one, two, three or more, may provide for the restriction of rolling, it will be seen that the primary purpose of the water mooring anchors for controlling vertical movement, namely, surplus lift may be dispensed with after the ship has been landed, that is moored to the surface in the case of a double nacelle keel with water-ballast arrangement. Nevertheless, during the period of mooring for discharge and embarcation, conditions may warrant maintaining the vertical or surplus lift anchors, as well as a portion of water-ballast keel counterbalanced for the airship lift, after it has once been drawn down to the water surface mooring.

In the particular construction illustrator in Figs. I to V the nacelle consists of the transverse frames 5, with the outer sheathing 6 and suitable longitudinal ribs 7, and may contain a central longitudinal bulkhead 8, and transverse bulkheads 9-9. At the lowest portion of the nacelle hull skin there are valves 10-10 suitably arranged, closing the openings 1111 which are preferably a series of ample area valves adjacent the keel 12 of the nacelle, to provide quick inlet and exit of water. Suitable strainers 13 above each valve opening are provided to prevent ingress of anything except water. Suitable rods or valve control stems 1t1 l extend through packing boxes 15 through the airtight roof of the nacelle, which may be the lower hull. skin of the airship. These rods reach to a position such as the hand wheels 16--16 within the hull of the airship, where they may be readily manipulated by the crew for the opening and closing of the valves 1010. space in the nacelle is indicated by a suitable remote gauge 17-17 and indicators adjacent the valve control wheels.

On board of the ship. at any suitable place, are pumps 1f 18 connected by pipes 19 19 to the uppermost area of the roof of the nacelle, at 2020, with air valves 212l positioned accessible to the operator of the valves,thus providing for one or two-man control of each set of water ballast valves, air control for water ejection, and indicators for the ballast condition in the nacelle. Suit.- able manholes for access for inspection and repair of the nacelle are provided in the airtight roof of the nacelle.

As shown in Figs. II, III and IV, lines of the nacelle keel provide a larger beam near the bow with a taper toward the stern, which is preferable, but maintaining a generally horizontal keel of the ballast nacelle, and at its stern a rudder 22 may be provided operated from the interior of the airship by suitable tiller or steering gear.

The method of mooring by this invention would involve bringing the airship under its air control elevators and rudders to the desired location, and as the keel touches the water some or all of the "alves 10-10 would be opened the desired extent to admit water into the nacelle, and their opening so controlled as to prevent too greata sinking of the nacelle below the surface of the water. While this is being accomplished the bow line 2 may have been run to the mooring mast, or under. light wind conditions the trim of The amount of water in the ballast the ship on the water may be first accomplished, and then the out-mooring line secured the desired extent of the ships-position. When so moored, with aisuitable small island mooring, the ship may be brought on a stable flotation to a point where the passsenger and supply hatch is accessible to a circular wharf around the mooring tower, thereby permitting ready access and egress.

However, the conditions of airship operation do not always permit a practical lowering of the ship to water level, that is it may involve too great a speed when dependent upon elevator control, or otherwise, and therefore under such conditions the liftanchorage method of bringing the ship down to the surface of the water may he acconr plished in the method indicated, and forms of construction shown, in Fi s. VI to IX. In such case the ship may be brought down to the desired level adjacent or on the water surface, and maneuvered or taxied to the more or less permanent mooring mast floating or on land.

In the case of the semi-permanent,mooring on the water, and when it is desired to leave the mooring the pumps 1818- are operated and the crew control by the valves the inlet of air to the top or roof of the ballast keel, thereby gradually forcing thewaterout of valves 10--1O as rapidly as desired, and after clearing the water by the release of the wa ter ballast the ship is prepared to cast ofi, that is by rising in still air, or in case of a wind it can clear from the bow, mooring, and take to the air. any chance of re naining 'ater may then be ejected by opening-the valves and driving ample air from the pumps, either one, or both, or by suitable valves to airpipes leading to each of the several longitudinal sectional compartments. When in the air the manholes may be removed and any desired inspection and cleaning of the interior of the nacelle-is acoomplished.

It is appreciated that landing in any fair,- way the chance of valves being clogged by debris, might interfere with the reasonable expectations of such landing operations. And in like manner the use of water ballast containers from the ship by the crew on board, would be equally subject to uncertain ties, so that the use of sponges lowered-away in cages offers the opportunity of absorbing and retaining water through a multitude of natural valves, with the capillary-action in the sponge, so that it affords guarantee of the absorption of about twenty times the weight of the material carried by the ship for this purpose. The quick absorption by sponges or like material may at times entail the priming of the sponges in order that their absorption of water is more rapid and complete, but in event the formation'otl the sponges affords the opportunity of the quick increase of'weight content, and, on the other hand, provides for a quick expulsion of a substantial amount of the weight, as inclicated in Fig. IX, and thereafter by drawing the sponge cage adjacent the crews quarters on the ship it is a simple matter to provide for the complete expulsion of the water and the dry storage of the sponges to minimize weight, with the added advantage that in case of emergency for the extreme lightening of ship ballast even the weight of sponges or other material of similar physical characteristics maybe jettisoned While a sock mightin some cases be used in place of the sponge-anchor, that is a container such as a canvas bag, collapsible and easily stored on board ship, or other form of anchor having the qualifications essential for the purposes herein described,any such means wouldrequire a valve to assure the inlet andexit of water. Therefore the use of sponges with the innumerable inlets for water, it will'be noted isunder certain circumstances to be preferredinstead of any anchor ballastspace dependent upon the functioning of valves.

It will thus be seen that in the practice of this invention the present (lay requirements for airship landing, namely a large ground crew and haul-down ropes, are unnecessary, and in place thereof'it brings a fixed part of the ships hull at its lowest portion, into cushioning contact with the surface of the water, thereby'relieving weight, but simultaneously it permits the taking on of ballast under absolute control, namely, by theopening of valves tothe desired degree. Then should the wind or the buoyancy, conditions of the ship tend to cause it to ascend, a slight rise of-the ship immediately brings into effect the counter-weight of the water ballastthat has been allowed toenter the ballast. hull at the bottom. Tons of water in this way, or only pounds ofv water, may be added to the ships ballast for stable flotation and may be definitely regulated, and in particular the weight of ballast in that; way acquired'may be quickly discharged in part or whole,all under the controlof' the crew on board. he sponge-anchors or their equivalent, may be usedto bring'the ship down for water landing when it has no headway, and a suitable number and arrangement of such anchors may alone serve to maintain the ship in stable flotation on the surface in conjunction with the nacelle keel, without admitting waterballast to the keel. But it is preferable to use anchors for lowering the ship and then regulate the flotation by some water-ballast, so that the anchors may be cleared and the expulsion of the -rater-ballast used for getting under way, under entire and quick control of the crew.

The under-water lines of the nac-elle keel may be constructed in various ways to break contact from the water surface at the speed of Lil takeoff; while also supplementary propellers, or a propeller operated through gear from the ship may be used for the minor maneuvers of the ship when moored on the water.

In Figs. VI, VII, VIII and IX the airship 1 has the nacelle 2% which may be arranged and equipped like the nacelle shown in the previous figures, or may be only for flotation purposes to counteract the weight pro vided by the hold-down-anchors. It may also have one or more break-water keels 25 to cushion the landing of the ship on the water by providing a gradual einersion of the nacelle. In compartments 26*26, located fore-and-aft where they will prefera ly be above any emersion, suitable gear, such as the reel 27, provides for manipulating a. chor-cables 28 passing out of the hull on either side over suitable sheaves and guides at 29-29. These lines 28 are each attached to an anchor 30. In the form shown the anchor is a cage containing sponges, and another line 31 from each cage leads to compartment 26, thus providlng means for pulling the anchor inboard within the grasp of the crew, in order to fully expel the water from the sponges and stow away that landing gear when in flight. In the form shown in Fig. IX a second line 32 runs to the ship passing through the guide 33 and secured at 34 to a plurality of radiating lines 35, which in turn are secured to joints 36' in the hinged connections of the bot-tom of the cages 37. In this form provision is made for the sponges to be spread out when absorbing water and functioning in a weight capacity, and when it is desired to lighten the ballast preliminary to weighing anchor, the line 32 is first hauled in and through the connections with the lower members of the cage or basket, it compresses the mass of sponges, expelling the water and thereby lightening the weight of the anchors until they can be hauled close to the ship and inboard by lines 31 to complete the drying of the sponges.

As shown in Fig. VI the anchors are emersed with the ships keel above the surface of the water, in the operation of lowering the ship for a water landing. In Fig. VII an end View shows the ships nacelle 2e emersed in the water with the anchors also emersed, thus providing central flotation and lateral control, the balance of which may be regulated by the crew, and during the mooring the anchor lines as well as the nacelle ballast, if water has been admitted, will be constantly under the control of the crew for trimming of ship to meet the aero-static conditions, and also to vary the flotation with any variation of load by taking on or discharging cargo, supplies or personnel.

It will thus be seen that by my invention an airship may be made stable for flight with a keel that can be a complementary part, or an integral part of the lower keel structure of an airship, and the moment water landing is desired, the manipulating of the permanent equipment of the ship provides for grasping a sufficient ballast or load weight, controlled entirely by the ships crew, in order that the ship be brought down to the surface, and then held down to the surface of the water in stable flotation. 1V ith this condition, the ships crew alone is in a position to release part or all of the ballast, synchronized with all other operations of getting the ship under way.

While the use of a specially arranged islet with a mooring tower or mast has certain advantages, the invention is of particular importance for mooring to watercraft, by lying in their lee, or mooring to a shore tower with a constant prevailing off-shore wind, or under suitable conditions mooring on the surface of the water without depending upon any floating or stationary mooring mast or like device.

Various additional advantages will be realized from the practice of my invention, and many variations in the construction, beyond the particular forms herein specifically shown and described, may be made without departing from my invention.

lVh-at I claim and desire to secure by Letters Patent is:

1. An airship having self-contained means for adding temporarily to its load a controlled amount of water, said means including a submersible anchor controlled by a cable from the ship to a water surface, and means integrally incorporated in the lower portion of the ship for buoyancy on a water surface, and having controlled means for the admission and expulsion of water-ballast.

2. A rigid airship having integrally embodied with its structure a hull a substantial length of the lowest portion of the ship adapted to ride on a water surface, means incorporated therewith for admitting waterballast and expelling water-ballast, and one or more water-anchors adapted to be lowered and retracted from the ship to take an increased water load for lowering said ship to the surface for the engagement of the integral structure of the ships bottom and the emersion thereof in the Water, whereby the ship may be brought to a water surface and moored thereon in stable flotation by means entirely controlled by the ships crew.

3. A rigid airship having one or more pairs of sea-anchors embodying means for acquiring and retaining an added water load, means on the ship for lowering and hoisting said sea-anchors, one of each of said pair of sea anchors being on opp site sides of the keel of the ship, whereby lateral trim and rolling of the ship may be controlled by the crew.

4. A rigid airship having self-contained means for lowering and raising a dependent cage or the like containing sponges, or material of similar physical characteristics.

5. A rigid airship having a Watertight keel for part of its length extending below the main hull for a minor part of the length of the ship and having its sides converging to a narrow kelson and having an airtight roof and means on board ship above the airtight roof adapted to control the admission of air into said keel, and one or more valves permitting ingress and exitof water from the bottom of the keel, said means of control therefor closely assembled in an operating compartment of the ship.

6. In an airship, a rigid hull structure with a rigid longitudinal girder extending along the bottom of the main hull, a water chamber structure supported below a minor part of said main hull structure and having stream lined sides extending from the skin of the main hull with sides sharply converging to a narrow kelson, water-ballast inlets at the lowest part of said water-ballast hull, and controlling means therefor actuated from a part of the main hull.

7. In an airship self-contained means operable by the ships crew to add water load from an underlying body of water, means associated therewith to draw the ship to the surface of the water, and means for floating contact of the keel of the ship on the water surface and for controlling excess water-ballast in the keel.

8. A rigid airship having self-contained means operable by its crew to add a remote water-weight from a water-body below the ship, means on the ship for drawing the ship to the below lying water surface, and means for resisting the submersion of the ship beyond the keel, whereby the airship may be drawn to the water surface and maintained in stable flotation under the control of its own crew.

9. A method of mooring airships consisting of lowering away from the ship means acquiring added dead weight from an underlying body of water, drawing the ship down by the resistance of such excess temporary weight without unnecessary reduction in buoyancy of the ships flotation gas, bringing the ship to a semi-emersion of a keel section, thereupon manipulating water-ballast in the keel in conjunction with the superwater-load means, and maintaining thereby stable flotation on the water surface.

10. The method as set forth in claim 9, having as an additional operation the mooring of the ship by-the-bow to a strain-resisting object, and adjusting the trim in respect of the bow strains, keel flotation and temporary excess loads into stable flotation against rise and fall and rolling.

11. A rigid airship having self-contained means for lowering and raising a dependent cage or the like containing sponges, means embodied in said cage and remote control on the ship for evacuating the water from said sponges.

12. A rigid airship having self-contained means for manipulating a dependent cage or the like adapted to absorb a water load, and means on the ship for controlling the absorption or evacuation of said water load in the dependent cage.

13. A rigid airship having self-contained means for raising or lowering a cage or the like equipped for absorption of water by capillary action, and remote control on said ship for evacuating the water.

14. An airship having self-contained means for controlling a remote water load dependent from the ship, said water load comprising sponges or the like, and having means for squeezing or otherwise evacuating the water from said sponges under control from the ship.

15. A rigid airship having one or more dependent cages for sponges, means on the ship for lowering or raising each cage, and means on the ship for reducing the water content in said sponges.

16. A method of mooring airships consist- 7 ing of lowering from the ship means for capillary or like absorption of water underlying the ship, drawing the ship down by the deadweight due to the absorbed water in said means, bringing the ship to contact with the water surface, and thereupon maintaining stable flotation on the water surface by the control of waterweight.

In testimony whereof, I have signed my name to this application, this 13th day of January, 1930.

CARL B. FRITSCHE. 

